A polycarbonate resin is a polymer material having good transparency, impact strength, and molding processability, and is widely used as an exterior material of portable electronic devices. Recently, it is common to adopt a large display window for a portable electronic device such as a mobile phone in response to the popularization of smartphones. A mobile phone in which a display is supported by a general metal bracket can be prepared by insert molding to integrate the metal bracket by surrounding the metal bracket through plastic injection molding.
In insert molding, a polycarbonate resin composition is positioned along a border part, and surrounds the border of the metal bracket. Thus, it is vulnerable to impact resistance and fatigue resistance as stress is concentrated. In particular, a portable electronic device is frequently exposed to chemical products including various cosmetics, and the like by frequent touch due to its nature. Thus, it is problematic that the physical properties such as the mechanical properties and impact strength of a polycarbonate resin composition are degraded by the chemical products.
In order to solve such problems, U.S. Pat. No. 4,188,314 discloses a shaped article having enhanced chemical resistance, including polycarbonate and copolyester derived from isophthalic acid, terephthalic acid, and 1,4-cyclohexanedimethanol. However, its mechanical properties can be poor, and sufficient impact strength may not be obtained.
Therefore, there is a need for a polycarbonate resin composition having excellent chemical resistance and fatigue resistance, while maintaining the mechanical properties such as tensile strength and impact strength, and the inherent properties such as dimensional stability, thermal resistance, transparency, and molding processability of a polycarbonate resin.